Facebook is not the only social network where your reach can be limited. If people are using Twitter search to locate information, they have to specifically click "All" to see all tweets or profile bios with a specific keyword.

Developers also have the option to use a filter in the Twitter APi that will value tweets as none, low, medium, or high meaning that users of those applications may miss out on tweets that algorithmically check out as having little value. So again, small businesses not investing in advertising may see a decline in engagement.

In short, you can't just assume that if your target audience is on Facebook or Twitter at the time you post a new update, they will see it.

More importantly, when it comes time so have a sales conversation with your audience, email simply out performs social media.

Custora recently did a study that analyzed data from 72 million customers shopping on 86 different retailer sites.

They found that over the past four years, online retailers have quadrupled the rate of customers acquired through email to nearly 7 percent.

Meanwhile Facebook and Twitter barely registered.

They also found that the average customer lifetime value (CLV) of users acquired via email is considerably higher than those coming from social media.

However, email is not just a superior channel for customer acquisition. Some people are seeing it drive way more traffic than social as well.

Noah Kagan recently sent a tweet to his 13,000 Twitter followers. It got 109 clicks for a click-through-rate (CTR) of 0.8%.

He sent the same information to his email list of 3,547 people and got 882 clicks for a CTR of 24.8%. An 8x improvement over Twitter. (Hat tip to Justin Premick for this info).

The reason email is so much more effective at driving traffic and sales is because you get to take the conversation about your products and business to your customers most personal online space - their inbox.

While platforms like Facebook and Twitter are great for free content distribution and engaging your community, they're also noisy and your audience may not be on them when you post an update.

Email, however, gets seen every time.

Google is Making Search Rankings Harder to Acquire

As the CLV graph above shows, customers coming from both paid and organic search are extremely valuable to your business. However, climbing the search rankings in Google is getting harder and harder.

For those that keep up with the latest in search engine optimization news, you probably know that a lot of the tried and true methods that SEO's have used in the past to gain higher keyword rankings are being devalued by Google.

Algorithmic changes have (rightfully) targeted low quality content (building links via article marketing and blog networks), keyword-based anchor text (trying to rank your men's clothing company by creating a high volume of links using that term), paid links (typically links that are sitewide in sidebars or footers), and many other linking strategies.

This has put many businesses that have used these into the famed Google penalty box, and many more business in a state of constant fear that they may lose their rankings in the future.

Most of the SEO strategies that are safe and work well (like content marketing) take time to build upon before desired rankings are achieved, leaving new businesses with only one option to get on the first page quickly: buying Google AdWords. The ins and outs of PPC can be enough to make ones head spin.

This is why businesses that are investing in PPC to build their mailing list. This way, instead of just getting a potentially one-time click in search, they are opening the door to future communications with their target customer base. One that they don't have to worry about getting penalized.

Email is Content Marketing's Best Friend

Content marketing is undoubtably the hottest marketing strategy right now because it can help you in both of the above areas. It gives you something to share and promote on social media, and it also helps you earn more rankings in search results.

The trouble with it is, quality content takes a major investment. First, you have to decide what to focus on. Do you want to have text-based blogs posts? Video explainer videos and commercials? Slideshare presentations? Fun and informative podcasts? Viral infographics?

Then, you have to decide who is going to create all of that content for you. Do you have an in-house team of content creators? Do you outsource? How do you find someone who excels at creating different types of media?

In other words, content marketing is tough. The thing is, it works. Really, really well.

And that's why collecting email addresses from your visitors is so important. It gives you a way to keep in touch and follow up with them over time and ensures all the time and money you've spent on creating content isn't just resulting in one-time visits.

Not to mention building a mailing list to consume your content is going to help increase your overall conversions as you will see more purchases from your email list than your blog readers, YouTube subscribers, or podcast listeners as mentioned above.

Email Drives Traffic and Sales

Now that you know why you need a mailing list of your ecommerce business, let's take a look at what you can do with it. Depending on the service provider you choose to deliver your email content, you can use your mailing list to reach your customers in a wide variety of ways (which we'll be exploring more deeply in future posts).

Here are just some ideas to get you excited.

Let customers know about your new products and other interesting company news that affects them.

Set up autoresponders - a series of drip emails with a goal of getting a customer to buy or learn more about your products over time.

Send timed discounts for holidays, birthdays, and other personal events (anniversaries, for example).